Avalanche Forecast

High -

Friday: Cloudy with scattered flurries bringing 2-5 cm of new snow, mainly in the afternoon and overnight. Light southwest winds. Alpine high temperatures to -5.Saturday: Mainly cloudy with isolated flurries and a trace of new snow. Light to moderate southwest winds. Freezing level rising to 1400 metres with alpine high temperatures to -2. Mild temperature inversion.Sunday: Mainly sunny with valley cloud due to temperature inversion. Light southwest winds. Freezing level to 1700 metres with alpine temperatures to +2. Cooler at lower elevations.

Reports from Wednesday show a continuation of recent heightened avalanche activity involving both storm slabs above the January 5 surface hoar layer as well as the deeper December 15 surface hoar. Avalanche activity on these interfaces continues to be extensive, with natural and remote (from a distance) triggers forming a large percentage of observations. Sizes have ranged from Size 1-3, slab depths have generally ranged from 40-80 cm, and activity was observed on all aspects and elevation ranges. Reports from the previous two days showed similar activity.Some of the notable themes that are emerging from recent activity include accidental and remote triggering, 'step down' release types, releases on surprisingly low angle, supported terrain, and wide fracture propagations.Looking forward, expect a continuation of heightened human triggering potential that may increase toward the weekend with forecast warming.

Recent storms brought 50-70 cm of new snow to the region. The new snow sits on surface hoar on sheltered slopes as well as sun crust on steep solar aspects. Numerous storm slab avalanches resulted as the new snow formed a slab before bonding to the surface. Moderate to strong southwest winds accompanied the snowfall at higher elevations, creating wind slabs in lee features.As the new snow continues to consolidate, it forms a dangerous slab above several persistent weak layers that exist in the snowpack. The first of these is the (January 5) surface hoar that exists at the new snow interface. Recent snowpack tests and avalanche activity show a high degree of reactivity at this layer. Below it, another surface hoar layer from late December 26 is showing increased involvement in 'step' down releases in the region. This layer is found at similar depths, but just below the January 5 interface.Below these layers, the December 15 surface hoar is now buried 70 to 110 cm deep. This layer has been the failure plane in many recent destructive slab avalanches, with many of these 'stepping down' to this layer from shallower releases. Its reactivity has been most apparent at treeline and below.